Diagnosis And Testing; Preliminary Diagnosis; Fluid Level And Condition; Vehicle Is Driveable - Jeep 1987 Wrangler Workshop Manual

AUTOMATIC TRANSMISSION
S i r
DIAGNOSIS AND TESTING
PRELIMINARY DIAGNOSIS
The preliminary diagnosis is the first step in the
diagnostic sequence. Two basic procedures
are involved. The first procedure is for vehicles
that are driveable. The second procedure is for
vehicles that will not back up or move forward.
Vehicle Is Driveable
Verify engine operating condition.
Check transmission fluid level and condition.
Adjust the throttle and gearshift linkage before
road testing if the complaint was based on
delayed, erratic, or harsh shifts.
Perform a stall test if the complaint was based
on sluggish, low-speed acceleration or abnor-
mal throttle opening requirements to maintain
highway speeds.
Road test the vehicle and analyze the results.
Refer to Road Test and Road Test Analysis in
this section.
Perform hydraulic and air pressure tests if road
test analysis indicates this is necessary.
Vehicle Will Not Back Up or Move Forward
Verify proper engine operation.
Check transmission fluid level and condition.
Check for broken or disconnected throttle
linkage.
Check for broken cooler lines and loose or
missing pressure test port plugs.
Raise the vehicle, start the engine and shift the
transmission into gear.
• If the propeller shafts turn but the wheels do
not, the problem is in the differential or axle
shafts.
• If the propeller shafts do not turn and the
transmission is noisy, stop the engine. Re-
move the transmission oil pan and check for
debris. If debris is not present, remove the
transmission and check for a damaged drive
plate, drive plate bolts, converter hub, input
or output shaft, or oil pump.
• If the propeller shafts do not turn and the
transmission is not noisy, perform a hydrau-
lic pressure test to determine if the problem
is related to a hydraulic or mechanical
component.
FLUID LEVEL AND CONDITION
Check fluid level and condition as follows.
WARNING: Keep hands or loose articles of
clothing away from the fan, accessory drive
belts or other rotating engine parts. Contact
with rotating or hot engine components can re-
sult in personal injury.
Drive the vehicle until the transmission fluid is
at normal operating temperature of approx-
imately 79.4°C (175°F).
NOTE: Avoid inaccurate fluid level readings. Do
not check fluid level until the fluid is at normal
operating temperature.
F
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